Pulse generator

ABSTRACT

The pulse generator disclosed comprises five magnetic reed switches disposed above a rotary magnetic disc and at equal angular intervals on a circle concentric with the disc and four permanent magnet pairs disposed on the disc to selectively face the switches during rotation of the disc such that selected two of the switches are put in their closed position for each of incremental rotations of the disc. In this way 10 different coded outputs are provided.

United States Patent Hayashi et al. [4 1 Mar. 21, 1972 s41 PULSEGENERATOR 3,233,060 2/1966 Wintriss .;..33s/207 x 3,451,053 6/ i969Xenis et al. ..335/205 [72] Inventors: Masayuki liayashi; MitsunoriYamane, v

Fukuyama Japan Primary Examiner-Hemard A. Gilheany Assistant Examiner-R.N. Envall, Jr. [73] Asslgnee' jzL Kabushiki Kaisha' Attorney-Robert E.Burns and Emmanuel J. Lobato [22] Filed: Dec. 24, 1969 [57] ABSTRACT[21] Appl. No.: 887,943 The pulse generator disclosed comprises fivemagnetic reed switches disposed above a rotary magnetic disc and atequal [30] Forelgn Application Pnomy Data angular intervals on a circleconcentric with the disc and four Jan. 6, 1969 Japan ..44/191s Permanentmagnet Pairs disposed on the disc to Selectively face the switchesduring rotation of the disc such that selected [52] US. Cl. ..335/207two of the Switches axe put in their closed Osman for each of P [5 1]Int. Cl. ..-.....H0lh 51/28 incremental rotations f the disc In this way10 difi of Search coded outputs are provided 307/106; 340/340 [56]Reierences Cited UNITED STATES PATENTS 2,929,896 3/1960 Ronning 33 yg9 8Claims, 7 Drawing Figures PULSE GENERATOR BACKGROUND OF THE INVENTIONThis invention relates to improvements in pulse generators suitable foruse in readout counters.

If the conventional type of pulse generators using magnetic reedswitches is incorporated into readout counters adapted to step forexample, 10 times per each complete revolution for the purpose ofproviding 10 coded outputs then it has been previously required todispose five magnetic reed switches on a rotary disc at different radialdistances from its center and to provide four pairs of permanent magnetsfor each of the reed switches. That is, the rotary disc has beennecessary to have disposed thereon five circular arrays different indiameter from one another and each including four pairs of permanentmagnets to successively oppose the associated reed switch duringincremental rotational movements of the rotary disc. Thus the magnetstotal 20 pairs. Each time the rotary disc steps, selected two of thefive reed switches are operated and therefore after the disc has stepped10 times to complete one complete revolution the reed switches each havebeen operated four times to provide the total of 10 different outputs.

The conventional pulse generators as above outlined have beendisadvantageous in that the rotary disc has been necessarily providedwith the permanent magnets as many as 20 to increase the weight of theresulting rotator structure leading to a slow response. Further aspacing between each pair of adjacent circular magnet arrays has beenrequired to be wide in order to prevent the permanent magnets in eacharray from magnetically interferring with those in the adjacent array.Therefore it has been difficult torender the resulting pulse generatorsmall-sized.

SUMMARY OF THE INVENTION Accordingly it is an object of the invention toprovide a new and improved pulse generation device decreased in weightand fast in response by having a plurality of magnetic reed switchesdisposed in a single circular array and having a minimum number ofpermanent magnets disposed in a single circular array on a rotary discto be successively opposed to the reed switches during the rotationalmovement of the rotary disc.

It is another object of the invention to reduce the magneticinterference between permanent magnets involved.

It is a more special object of the invention to provide a new andimproved pulse generation device for use in a readout counter capable ofproviding 10 different coded outputs with a simplestructure using fivemagnetic reed switches and four permanent magnet pairs.

The invention accomplishes the above cited objects by the provision of apulse generation device comprising a rotary disc-shaped supportresponsive to a measured quantity to effect an incrementalrotation, andplural pairs of permanent magnets disposed in a circularly arcuate arrayon the discshaped support and substantially equidistant from the centerof the disc-shaped support, each of the magnet pairs including the N andS pole faces, characterized by a plurality of magnetic reed switchesdisposed above the disc-shaped support and in opposite relationship withrespect to a path along which the permanentmagnets are rotated with therotational movement of the support.

Preferably, the disc-shaped support may be of a magnetic material andeach pair of the permanent magnets may include a pair of permanentmagnets having the respective pole faces of opposite polarity fixedlysecured to the support and the exposed pole faces capable of facing thereed switches during the rotational movement of the support.

In a preferred embodiment of the invention by which 10 different codedoutputs are provided for each complete revolution of the disc-shapesupport, five magnetic reed switches may be spaced away from each otherby angles of substantially 72 above the periphery of the support andfour pairs of permanent magnets disposed on the periphery of the supportby having the respective pole faces of opposite polarity of each pairfixedly secured to the support and the respective exposed pole facesthereof capable of facing the reed switches, the pairs of permanentmagnets being disposed at central angular intervals substantially equalto an angleof 36 except for two inner pairs thereof being disposed at acentral angular interval substantially equal to an angle of 72.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will become more readilyapparent from the following detailed description taken in conjunctionwith the accompanying drawings in which:

FIG. 1 is a schematic view of a pulse generation device constructed inaccordance with the principles of the invention and a driving unittherefor as viewed on the front side;

FIG. 2 is a view similar to FIG. 1 but illustrating the rear sidethereof;

FIG. 3 is a perspective view of the pulse generation device shown inFIGS. 1 and 2;

FIG. 4 is a side elevational view of the device as shown in FIG. 3;

FIG. 5 is a plan view of a special form of the invention;

FIG. 6 is a plan view useful in explaining the operation of the deviceshown in FIG. 5; and

FIG. 7 is a side elevational view of a modification 'of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawingand FIGS. 1 and 2 in particular, it is seen that an arrangementdisclosed herein comprises an electromagnet generally designated by thereference numeral 10 including anelectromagnetic coil 12 and a movableiron piece or armature 14. The coil 12 is adapted to be intermittentlyenergized with input pulses dependent upon an electric quantity measuredfor example by a wattmeter (not shown). The armature 14 is operativelyconnected to a spring loaded feed claw 16 which is, in turn, operativelycoupled to a digit dial 18 in the conventional manner. The digit dial 18can have disposed on the outer periphery the digit of 0, l, 2, 9 atsubstantially equal angular intervals in the named order (see FIG. 3).Each time the coil 12 is energized the armature 14 is attracted by theelectromagnet 10 to step the digit dial 18 in the direction of the arrowshown in FIG. 1 through the feed claw 16.

The digit dial 18 has fixedly extending through the center thereof arotary shaft 20 which is, in turn, provided on that portion thereofremote from the feed claw with a disc-shaped support 22 of any suitablemagnetic material such as iron for rotation with the digit dial 18. Thesupport 22 is provided on the exposed surface with a plurality ofpermanent magnets 24 disposed at substantially predetermined angularintervals on a circle having the center lying on the axis of rotation ofthe same with one pole of each magnet fixedly secured to the exposedsupport surface. Only for purpose of illustration FIGS. 1 and 3 showfour of the permanent magnets 240, b, c and d. As best shown in FIG. 4the permanent magnet 240 has the N pole fixedly secured to the support28 and the S pole exposed while the magnet 24b has the S pole fixedlysecured to the support 22 and the N pole exposed whereby both thepermanent magnets 24a and b form one portion of a closed magnetic paththrough the support 22 as will be described hereinafter. This is truethe case of the permanent magnets 24c and d.

As shown in FIGS. 1, 3 and 4, magnetic reed switches generallydesignated by the reference numeral 26 are suitably a length sufficientto bridge any pair of adjacent permanent magnets 24, a pair ofreed-shaped contact strips 30 and 32 of any suitable resilient, magneticmaterial such as iron sealed through the opposite ends of the envelope28 with the inner end portions the strips within the envelopeoverlapping each other to form a narrow gap therebetween. The contactstrips may have preferably their surfaces plated with any suitableconductive material. The contact strips 30 and 32 have the outer endsdisposed outside the envelope 28 and adapted to be electricallyconnected to any suitable external circuit (not shown).

While the single reed switch 26 is illustrated it is to be understoodthat any desired number of the switches 26 may be used to operativelyassociated with any desired number of the permanent magnet pairs for theparticular application.

As an example, the invention will now be described in conjunction withan arrangement using four pair of permanent magnets and five magneticreed switches to provide 10 different output corresponding to values of0, l, 2, 9 respectively during one complete revolution of thedisc-shaped support.

Such an arrangement is illustrated in FIG. 5 and 6 wherein likereference numerals designate the components identical to those shown inFIGS. 1, 3 and 4. As shown in FIGS. 5 and 6, five magnetic reed switches26-I, II, III, IV, V are disposed at substantially equal angularintervals, in this case, equal to the angles of 72 on the periphery ofthe disc-shaped magnetic support 22, in spaced relationship with respectto the support 22 at the substantially same level and have preferablytheir centers substantially aligned with the centers of the alternatedigits labeled on the peripheral surface of the digit dial 18 as will beready understood from FIG. 3. For example, if the reed switch 26-Icenter is substantially aligned with the center of the digit the reedswitch 26-V has its center substantially aligned with the center of thedigit 2 and so on.

Also four pairs of permanent magnets 24a, b, c, d, h are fixedly securedat predetermined angular intervals on the discshaped support 22 and inpredetermined positional relationship with respect to the reed switches26. More specifically, as best shown in FIG. 6, the two pairs ofpermanent magnets 24a, b and c, d are disposed at a central angularinterval substantially equal to an angular of 36 on the periphery of thesupport 22 such that the exposed or free pole faces of the two adjacentmagnets can selectively face the reed swiches with the center betweenthose pole faces substantially aligned with the center of that reedswitch overlapping them. Further two pairs of permanent magnets 24e, fand g, h are similarly disposed at a central angular intervalsubstantially equal to an angle of 36 on the periphery of the support 22in the same manner as above described. However inner pair of magnets 24cand d are spaced away from the inner pair of magnets 24e and f by acentral angular interval substantially equal to an angle of 72. This is,the pairs of permanent magnets are disposed at a central angularintervals substantially equal to angles of 36 except for the two innerpairs of permanent magnets being disposed at a central angular intervalsubstantially equal to an angle of 72. Thus it will be appreciated thatfour pairs of permanent magnets 24a, b, h, are secured on thedisc-shaped support 22 and on the same circle as the reed switches 26.

It is, however to be understood that the invention is not restricted toor by the arrangement of FIG. 5.

The arrangement as above described is operated as follows: It is assumedthat during the rotational movement of the support 22 in the directionof the arrow shown in FIGS. 5 and 6 the permanent magnets 24a and b ofopposite polarity have faced the reed-shaped contact strips 30 and 32 ofthe reed switch 26-I respectively as shown in FIG. 6. Under the assumedcondition, there is formed a closed magnet path traced from thepermanent magnet 24a through the S pole face of the magnet 240, thecontact strips 30 and 32 of the switch 26-I, the N and S pole faces ofthe permanent magnet 24b and the support 22 and thence back to thepermanent magnet 24a through the S pole face thereof. Therefore theinner end portions of the strip are magnetically attracted by eachother. That is, the reed switch 26 is put in its closed position.

As the same time the reed switch 26-IV is put above the magnet pair 16 has shown in FIG. 6 and therefore similarly 5 in its closed position.From FIG. 6 it is seen that none of the remaining reed switches islocated above any permanent magnet pair and maintained in their openposition. This can be caused to correspond to the digit 0" for example.I A further rotation of the support 22 will cause the permanent magnets24b and c of the same polarity to be put directly below the reed switch26-I. At that time the N pole faces of the magnets 24b and c face thecontact reeds 30 and 32 of the reed switch 264 to exert a magneticrepulsion upon both strips thereby to forcedly separate them from eachother even though the remanence due to the previous contacting thereofstill retains. Thus the reed switch 264 is put in its open position.Also the reed switch 26-IV is put in its open position because it ismagnetically coupled to the magnet 26h alone.

After the support 22 has been rotated from its position as shown in FIG.6 through an angle of 36, the permanent magnets reach their positionsrelative to the reed switches as illustrated in FIG. 5. In FIG. the reedswitches 26-I and 26-V are located above the respective magnet pairs 26cd e f and put in their closed position as will be readily understoodfrom the description made in terms of the magnet pair 26a b. However theremaining reed switches are in their open position. I This correspondsto the next succeeding digit, in this case, the

digit 2." I 30 Each time the support 22 has been rotated through anangle of 36 the process as above described is repeated to put selectedtwo of the five reed switches in their closed position while theremaining switches are maintained in their open position. Thus thesucceeding digits are coded by the particular selected two of the fiveposition. As the number of combination of5 in 2 is of -,C or the digits0, l, 9 can be definitely expressed by selected two of the five reedswitches put in their closed position.

From the foregoing description and the illustration of FIGS. 5 and 6 itwill be appreciated that each rotation through an angle of 36 of thedigit wheel 18 or disc-shaped support 22 causes only the particular twoof the five reed switches to be selectively put in their closed positionin accordance with the following chart while the remaining switches aremaintained in their open position. In the chart, the heading on eachcolumn means the particular digit to be indicated, and the referencenumerals in the leftmost column designate the reed switches shown at bythe same reference numerals in FIGS. 5 and 6. The particular reedswitches put in their closed position as the case may be are labeled ON.For example, the reed switches 26-I and 26-III are put in their closedposition for the digit (4. ,1

The above chart is shown only for purpose of illustration and it is tobe understood that the invention be not restricted thereto or therebyand that the digits to be indicated may be coded in various mannersdifferent from the encoding manner as above described.

If desired, each pair of adjacent permanent magnets including the freepole faces of opposite polarity may be replaced by a single permanentmagnet 26 disposed circumferentially of the support 22 as shown in FIG.v7 wherein like reference numerals designate the componentscorresponding to those shown in FIG. 4. In that event the support 22 isnot required to be formed of a magnetic material.

Also it is to be noted that the invention is equally applicable tovarious devices other than the readout counters.

What we claimed is:

l. A pulse generating device comprising a rotatable discshaped supporthaving opposite end faces, a plurality of pairs of permanent magnetsdisposed in a circle of selected radius on one said end face of saidsupport, each said pair of magnets having magnetic poles of oppositepolarity facing axially away from said support with pole faces disposedin a plane perpendicular to the axis of said support, a plurality ofmagnetic reed switches, means supporting said reed switches in a singlecircular array having a radius equal to the radius of said circle ofsaid magnets, said reed switches being disposed in a plane parallel toand slightly spaced axially with respect to the plane of said pole facesin position to be juxtaposed to and actuatable by said magnets, eachsaid reed switch having a length sufficient to bridge the distancebetween the magnets of a pair, and means for incrementally rotating saiddisc-shaped support to bring selected magnet pairs opposite selectedreed switches and thereby selectively actuate said switches.

2. A pulse generation device as claimed in claim 1 wherein said supportis of a magnetic material and each of said permanent magnets include onepole face fixedly secured to said support and the other pole faceselectively facing said magnetic reed switches during the rotationalmovement of said support.

3. A pulse generation device as claimed in claim 1 wherein said eachpair of permanent magnets is formed of a single permanent magnetincluding the N and S pole faces capable of selectively facing saidmagnetic reed switches.

i 4. A pulse'generating device according to claim 1, wherein the twomagnets of each said pair of magnets are equidistant from the axis ofsaid support and said reed switches are elongated and disposed withtheir lengths tangential to said circle in which said reed switches arearranged.

5. A pulse generating device according to claim 1, wherein .each saidreed switch comprises an enclosed elongated envelope and a pair ofreed-shaped contact strips of resilient magnetic material sealed throughopposite ends of said envelope and overlapping within said envelope toform a narrow gap therebetween.

6. A pulse generating device according to claim 5, wherein said contactstrips are coated with conductive material.

7. A pulse generating device. according to claim 1, wherein five saidmagnetic reed switches are disposed at approximately equal angularintervals of 72 and four pairs of said permanent magnets are disposed atangular intervals which are approximately integral multiples of 36whereby two selected magnetic switches are actuated for each of theincrements of rotation of said support to provide less different codedoutputs for each complete revolution of said support.

8. A pulse generating device according to claim 7, wherein the angularinterval between first and second and between

1. A pulse generating device comprising a rotatable disc-shaped supporthaving opposite end faces, a plurality of pairs of permanent magnetsdisposed in a circle of selected radius on one said end face of saidsupport, each said pair of magnets having magnetic poles of oppositepolarity facing axially away from said support with pole faces disposedin a plane perpendicular to the axis of said support, a plurality ofmagnetic reed switches, means supporting said reed switches in a singlecircular array having a radius equal to the radius of said circle ofsaid magnets, said reed switches being disposed in a plane parallel toand slightly spaced axially with respect to the plane of said pole facesin position to be juxtaposed to and actuatable by said magnets, eachsaid reed switch having a length sufficient to bridge the distancebetween the magnets of a pair, and means for incrementally rotating saiddisc-shaped support to bring selected magnet pairs opposite selectedreed switches and thereby selectively actuate said switches.
 2. A pulsegeneration device as claimed in claim 1 wherein said support is of amagnetic material and each of said permanent magnets include one poleface fixedly secured to said support and the other pole face selectivelyfacing said magnetic reed switches during the rotational movement ofsaid support.
 3. A pulse generation device as claimed in claim 1 whereinsaid each pair of permanent magnets is formed of a single permanentmagnet including the N and S pole faces capable of selectively facingsaid magnetic reed switches.
 4. A pulse generating device according toclaim 1, wherein the two magnets of each said pair of magnets areequidistant from the axis of said support and said reed switches areelongated and disposed with their lengths tangential to said circle inwhich said reed switches are arranged.
 5. A pulse generating deviceaccording to claim 1, wherein each said reed switch comprises anenclosed elongated envelope and a pair of reed-shaped contact strips ofresilient magnetic material sealed through opposite ends of saidenvelope and overlapping within said envelope to form a narrow gaptherebetween.
 6. A pulse generating device according to claim 5, whereinsaid contact strips are coated with conductive material.
 7. A pulsegenerating device according to claim 1, wherEin five said magnetic reedswitches are disposed at approximately equal angular intervals of 72*and four pairs of said permanent magnets are disposed at angularintervals which are approximately integral multiples of 36* whereby twoselected magnetic switches are actuated for each of the increments ofrotation of said support to provide less different coded outputs foreach complete revolution of said support.
 8. A pulse generating deviceaccording to claim 7, wherein the angular interval between first andsecond and between third and fourth pairs of said permanent magnets isapproximately 36* and the angular interval between said second and thirdpairs is approximately 72*.